From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B840C433DB for ; Mon, 1 Mar 2021 22:02:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E813C60232 for ; Mon, 1 Mar 2021 22:02:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239558AbhCAWCB (ORCPT ); Mon, 1 Mar 2021 17:02:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:48860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238408AbhCAR0t (ORCPT ); Mon, 1 Mar 2021 12:26:49 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id EC4F46508A; Mon, 1 Mar 2021 16:51:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614617463; bh=hSkNp1NvdvfcT7CqADL02pQ+TuBBbzb+7n0pWphzKDk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fPjqaku+oDlPNm5rMNJ7tHGwZnV0WoHAijuWUJN4lcdSqiFHWYh0xAqqsqxl0yGkw kb7q7s8JB1gQD6GE1joQ+bWeJqd/bc5TEdlZZpeVNYqlrI61ZbhKGv+Dylh9ad77jw pBbMokbWjtbMh22HjPxKmUZLDZir4Dk3o/NfjEHs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ezequiel Garcia , Philipp Zabel , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 5.4 082/340] media: imx: Fix csc/scaler unregister Date: Mon, 1 Mar 2021 17:10:26 +0100 Message-Id: <20210301161052.361891265@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161048.294656001@linuxfoundation.org> References: <20210301161048.294656001@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ezequiel Garcia [ Upstream commit 89b14485caa4b7b2eaf70be0064f0978e68ebeee ] The csc/scaler device private struct is released by ipu_csc_scaler_video_device_release(), which can be called by video_unregister_device() if there are no users of the underlying struct video device. Therefore, the mutex can't be held when calling video_unregister_device() as its memory may be freed by it, leading to a kernel oops. Fortunately, the fix is quite simple as no locking is needed when calling video_unregister_device(): v4l2-core already has its own internal locking, and the structures are also properly refcounted. Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device") Signed-off-by: Ezequiel Garcia Reviewed-by: Philipp Zabel Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/staging/media/imx/imx-media-csc-scaler.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/staging/media/imx/imx-media-csc-scaler.c b/drivers/staging/media/imx/imx-media-csc-scaler.c index 2b635ebf62d6a..a15d970adb983 100644 --- a/drivers/staging/media/imx/imx-media-csc-scaler.c +++ b/drivers/staging/media/imx/imx-media-csc-scaler.c @@ -866,11 +866,7 @@ void imx_media_csc_scaler_device_unregister(struct imx_media_video_dev *vdev) struct ipu_csc_scaler_priv *priv = vdev_to_priv(vdev); struct video_device *vfd = priv->vdev.vfd; - mutex_lock(&priv->mutex); - video_unregister_device(vfd); - - mutex_unlock(&priv->mutex); } struct imx_media_video_dev * -- 2.27.0